Wildlife biologist Dr. James Duncan tramps through the deep snow covering an abandoned farm field -- some 60 kilometres northeast of Winnipeg -- towards a grove of Manitoba maples situated near a battered old barn.

A great grey owl, Manitoba's provincial bird, is perched on the tip of a broken branch.

The raptor's dusky colouration blends in with the tree's own dark grey bark on this bright but cold mid-March day on the fringes of Netley Marsh near Lake Winnipeg. Duncan and his wife, Patsy Duncan, as they have done many times before over the past three months, have been driving across rural Manitoba, trying to spot, capture, band and measure great greys and northern hawk owls.

The couple has been conducting an ecological study of both species for the past 27 years -- ever since they were both student researchers at the University of Manitoba.

Jim, who moved here from Montreal some 30 years ago to study great grey owls, was doing small mammal trapping at the time as part of his owl study for a PhD. Patsy was his undergraduate volunteer assistant.

But a lack of supervision led to romance, as well as field research, Jim joked.

"There are not very many husband-and-wife couples who work together doing this type of work," said local ornithologist/owl specialist Dr. Robert Nero, 90, the person who introduced the couple to each other back in 1986.

"What we know about wildlife is the result of the dedicated research done by people like Jim and Patsy. There are a limited number of such couples who work together doing fieldwork. Their enthusiasm and knowledge is passed on to other people, young and old alike."

In order to try and capture the owl, Duncan, who is the director of the wildlife branch for Manitoba Conservation and Water Stewardship, carries a fishing rod at the end of which is attached a fur covered wooden lure shaped like a vole.

Meadow voles are the primary prey species of great grey owls.

He casts out the fish line and slowly reels it back. On his third attempt, the owl glides down from its perch. As it swoops onto the lure, Duncan captures it with a fish-landing net.

Back in the vehicle, he hands the bird, whose wide face is shaped like a satellite dish, over to Patsy. She whispers gently to the restless raptor, while holding it by the legs in the crook of her arm.

The couple works quickly. Jim places a small numbered metal band on one of the owl's legs. He explains this will help in the identification of the bird (so that various aspects of the bird's life can be studied by the measurements taken during the capture) if it should ever be caught again.

Jim also places the owl's head and body into a soft nylon bag and then weighs the bird on a small hand-held brass-spring scale. He then takes measurements of the tail length, the footpad to determine its sex (male), because an owl's sexual organs are internal, and the wing cord from wrist to the tip of the longest flight feather.

In the meantime, Patsy also is writing all the information down in a notebook.

The whole process lasts no more than 15 minutes and then the aptly named Phantom of the Northern Forest is released.

Jim observed: "We have proved for the first time that the whole life history of our provincial bird, the great grey owl, is completely evolved to be dependent on one prey species, the meadow vole. So, it's interesting to reflect that the fate and population dynamics of this one species of owl is ruled by a small mouse-like creature."

"The owl research isn't just about the work, it's more about the lifestyle for us," said Patsy, who, along with Jim and their two young adult children, live in a renovated historic farm house near Balmoral in the Interlake region. "We've lived most of our lives close to nature. Studying owls has allowed us to live that way. It's fun. We enjoy it."

For the Duncans, it is all done in the name of love and science.

Why you should give a hoot

The great grey owl (Strix nebulosa), which became Manitoba's official provincial bird emblem in 1987, is ranked by birders as No. 6 among the 50 most-wanted birds on the continent.

The northern forest dweller, with a wingspan of 1.5 metres, is the largest North American owl, even larger than the heavier great horned owl and snowy owl.

Meadow voles are its main prey over most of this bird's range in North America.

Every three to five years, great grey owls and northern hawk owls migrate into southern Manitoba (and even beyond) from farther north in the province. This is called an "irruption." It happens when there is a "crash" in the vole population and these raptors have to seek food elsewhere.

The northern hawk owl (Surnia ulula) is smaller than the great grey owl. Male northern hawk owls are generally 36.0-42.5 centimetres long and weigh 300 grams. Females are slightly bigger with a length of 37.2-44.7cm and a mass of about 340g.

The northern hawk owl is one of the least studied and poorly understood birds in North America.

Over the past 27 years, local owl researchers Dr. James Duncan and his wife, Patsy Duncan, have captured, banded and done various measurements on over 1,600 great grey owls and over 500 northern hawk owls, as well as radio-marked 101 great greys (1985-1991) and one hawk owl.

Both types of owls and, in fact, all raptors, are protected species in Manitoba.

Dr. James Duncan's new book, The Complete Book of North American Owls (Thunder Bay Press) will have its official launch at McNally Robinson on April 13.

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